Active volcanoes in the world: February 26 – March 4, 2014

In last 7 days new activity was observed at 6 volcanoes, ongoing activity was reported for 10 volcanoes. This report covers active volcanoes in the world from February 26 – March 4, 2014 based on Smithsonian/USGS criteria.

New activity/unrest: | Kelut, Eastern Java (Indonesia) | Marapi, Sumatra (Indonesia) | Pacaya, Guatemala | Poás, Costa Rica | Popocatépetl, México | Tungurahua, Ecuador

Ongoing activity: | Aira, Kyushu | Chirinkotan, Kuril Islands | Chirpoi, Kuril Islands (Russia) | Colima, México border | Dukono, Halmahera | Etna, Sicily (Italy) | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaii (USA) | Shiveluch, Central Kamchatka (Russia) | Sinabung, Sumatra (Indonesia)

The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday, notices of volcanic activity posted on these pages are preliminary and subject to change as events are studied in more detail. This is not a comprehensive list of all of Earth's volcanoes erupting during the week, but rather a summary of activity at volcanoes that meet criteria discussed in detail in the "Criteria and Disclaimers" section. Carefully reviewed, detailed reports on various volcanoes are published monthly in the Bulletin of the Global Volcanism Network.

New activity/unrest

KELUT, Eastern Java (Indonesia) 
7.93°S, 112.308°E; summit elev. 1731 m

PVMBG noted that the Alert Level for Kelut was lowered to 2 (on a scale of 1-4) on 28 February.

Geologic summary: The relatively inconspicuous 1,731-m-high Kelut stratovolcano contains a summit crater lake that has been the source of some of Indonesia's most deadly eruptions. A cluster of summit lava domes cut by numerous craters has given the summit a very irregular profile. More than 30 eruptions have been recorded from Gunung Kelut since 1000 AD. The ejection of water from the crater lake during Kelut's typically short, but violent eruptions has created pyroclastic flows and lahars that have caused widespread fatalities and destruction. After more than 5,000 people were killed during the 1919 eruption, an ambitious engineering project sought to drain the crater lake. This initial effort lowered the lake by more than 50 m, but the 1951 eruption deepened the crater by 70 m, leaving 50 million cubic meters of water after repair of the damaged drainage tunnels. After more than 200 people were killed in the 1966 eruption, a new deeper tunnel was constructed, lowering the lake's volume to only about 1 million cubic meters prior to the 1990 eruption.

MARAPI, Sumatra (Indonesia)
0.381°S, 100.473°E; summit elev. 2891 m

According to news articles, an explosion at Marapi on 26 February produced an ash plume that caused ashfall in areas as far as 10 km S. According to PVMBG the Alert Level remained at 2 (on a scale of 1-4).

Geologic summary: Gunung Marapi, not to be confused with the better known Merapi volcano on Java, is Sumatra's most active volcano. Marapi is a massive complex stratovolcano that rises 2,000 m above the Bukittinggi plain in Sumatra's Padang Highlands. A broad summit contains multiple partially overlapping summit craters constructed within the small 1.4-km-wide Bancah caldera. The summit craters are located along an ENE-WSW line, along which volcanism has migrated to the W. More than 50 eruptions, typically consisting of small-to-moderate explosive activity, have been recorded since the end of the 18th century; no historical lava flows outside the summit craters have been reported.

PACAYA, Guatemala 
14.381°N, 90.601°W; summit elev. 2552 m

INSIVUMEH reported that during 27-28 February gas-and-vapor plumes from Pacaya rose 400-500 m above the crater. Ejected tephra drifted 600 m S and SW. INSIVUMEH and CONRED noted increased activity on 2 March; at 0515 Strombolian activity at Mackenney Crater ejected material as high as 800 m and lava flows descended the W flank. Explosions produced dense ash plumes that rose 2.5 km and drifted 15 km S, SW, and W. Ashfall was reported in El Rodeo (4 km WSW), Patrocinio (about 5 km W), and Francisco de Sales (5 km N). By the next day activity had decreased, but lava flows traveled as far as 1.3 km S. Ejected tephra again drifted 600 m S and SW.

Geologic summary: Eruptions from Pacaya, one of Guatemala's most active volcanoes, are frequently visible from Guatemala City, the nation's capital. Pacaya is a complex volcano constructed on the southern rim of the 14 x 16 km Pleistocene Amatitlan caldera. A cluster of dacitic lava domes occupies the caldera floor. The Pacaya massif includes the Cerro Grande lava dome and a younger volcano to the SW. Collapse of Pacaya volcano about 1,100 years ago produced a debris-avalanche deposit that extends 25 km onto the Pacific coastal plain and left an arcuate somma rim inside which the modern Pacaya volcano (MacKenney cone) grew. During the past several decades, activity at Pacaya has consisted of frequent Strombolian eruptions with intermittent lava flow extrusion on the flanks of MacKenney cone, punctuated by occasional larger explosive eruptions.

POAS, Costa Rica 
10.20°N, 84.233°W; summit elev. 2708 m

OVSICORI-UNA reported that at 0800 on 25 February officials at the Parque Nacional Volcán Poás noted that the gray crater lake had convection cells and weak fumarolic activity at the S edge of the lake around a cryptodome.  At 1203 a strong phreatic explosion from Poás was recorded by webcams at the N end of the lake. The explosion ejected water, steam, gas, sediment, and rock fragments over 400 m above the lake's surface. Most of the material fell back into the lake, and onto the W, N, and E parts of the crater walls. Fumarolic activity around the cryptodome and lake convection both increased after the explosion.

Geologic summary: The broad, well-vegetated edifice of Poás, one of the most active volcanoes of Costa Rica, contains three craters along a N-S line. The frequently visited multi-hued summit crater lakes of the basaltic-to-dacitic volcano, which is one of Costa Rica's most prominent natural landmarks, are easily accessible by vehicle from the nearby capital city of San José. A N-S-trending fissure cutting the 2,708-m-high complex stratovolcano extends to the lower northern flank, where it has produced the Congo stratovolcano and several lake-filled maars. The southernmost of the two summit crater lakes, Botos, is cold and clear and last erupted about 7,500 years ago. The more prominent geothermally heated northern lake, Laguna Caliente, is one of the world's most acidic natural lakes, with a pH of near zero. It has been the site of frequent phreatic and phreatomagmatic eruptions since the first historical eruption was reported in 1828. Poás eruptions often include geyser-like ejection of crater-lake water.

POPOCATEPETL, México 
19.023°N, 98.622°W; summit elev. 5426 m

On 26 February CENAPRED reported that, with support from the Navy, scientists aboard an overflight of Popocatépetl observed that lava dome 48 had been destroyed, leaving a funnel-shaped cavity about 80 m deep. A new dome 20-30 m wide was at the bottom of the cavity. On 27 February activity decreased considerably. During 27 February-3 March gas-and-steam plumes were observed drifting E, ESE, W, and NE. On 2 March an ash plume rose more than 2 km above the crater and drifted NE. On 4 March at 0552 an explosion ejected incandescent tephra 700 m onto the NE flank and produced an ash plume that rose 1.2 km. The Alert Level remained at Yellow, Phase Two.

Geologic summary: Popocatépetl, whose name is the Aztec word for smoking mountain, towers to 5,426 m 70 km SE of Mexico City and is North America's second-highest volcano. Frequent historical eruptions have been recorded since the beginning of the Spanish colonial era. A small eruption on 21 December 1994 ended five decades of quiescence. Since 1996 small lava domes have incrementally been constructed within the summit crater and destroyed by explosive eruptions. Intermittent small-to-moderate gas-and-ash eruptions have continued, occasionally producing ashfall in neighboring towns and villages.

TUNGURAHUA, Ecuador 
1.467°S, 78.442°W; summit elev. 5023 m

IG reported that activity at Tungurahua was at moderate levels during 26 February-4 March; cloud cover often prevented observations. On 26 February a small pyroclastic flow traveled 400 m down the N and NW flanks. Ashfall was reported in El Manzano (8 km SW) and Palictahua. The next day seismicity increased and inflation was detected at the summit area. Diffuse vapor plumes rose from the crater during 1-2 March. 

Geologic summary: The steep-sided Tungurahua stratovolcano towers more than 3 km above its northern base. It sits ~140 km S of Quito, Ecuador's capital city, and is one of Ecuador's most active volcanoes. Historical eruptions have all originated from the summit crater. They have been accompanied by strong explosions and sometimes by pyroclastic flows and lava flows that reached populated areas at the volcano's base. The last major eruption took place from 1916 to 1918, although minor activity continued until 1925. The latest eruption began in October 1999 and prompted temporary evacuation of the town of Baños on the N side of the volcano.

Ongoing activity

AIRA, Kyushu 
31.585°N, 130.657°E; summit elev. 1117 m

JMA reported that during 24-28 February two explosions from Showa Crater at Aira Caldera’s Sakurajima volcano ejected tephra as far as 1,300 m. Incandescence from the crater was detected during 24-26 February. The Alert Level remained at 3 (on a scale of 1-5). The Tokyo VAAC reported explosions during 27-28 February and 2-4 March. Plumes rose to altitudes of 1.2-4 km (4,000-13,000 ft) a.s.l. and drifted W, NW, NE, SE, and S during 28 February and 2-4 March. A pilot observed ash drifting at an altitude of 1.5 km (5,000 ft) a.s.l. on 2 March.

Geologic summary: The Aira caldera in the northern half of Kagoshima Bay contains the post-caldera Sakurajima volcano, one of Japan's most active. Eruption of the voluminous Ito pyroclastic flow accompanied formation of the 17 x 23 km caldera about 22,000 years ago. The smaller Wakamiko caldera was formed during the early Holocene in the NE corner of the Aira caldera, along with several post-caldera cones. The construction of Sakurajima began about 13,000 years ago on the southern rim of Aira caldera and built an island that was finally joined to the Osumi Peninsula during the major explosive and effusive eruption of 1914. Activity at the Kitadake summit cone ended about 4850 years ago, after which eruptions took place at Minamidake. Frequent historical eruptions, recorded since the 8th century, have deposited ash on Kagoshima, one of Kyushu's largest cities, located across Kagoshima Bay only 8 km from the summit. The largest historical eruption took place during 1471-76.

CHIRINKOTAN, Kuril Islands 
48.980°N, 153.480°E; summit elev. 724 m

SVERT reported that a thermal anomaly over Chirinkotan was observed in satellite images on 25 February and gas-and-steam emissions were observed on 27 February. Cloud cover obscured views on other days during 24 February-3 March. The Aviation Color Code remained at Yellow.

Geologic summary: The small, mostly unvegetated 3-km-wide island of Chirinkotan occupies the far end of an E-W-trending volcanic chain that extends nearly 50 km west of the central part of the main Kuril Islands arc. Chirinkotan is the emergent summit of a volcano that rises 3000 m from the floor of the Kuril Basin. A small 1-km-wide caldera about 300-400 m deep is open to the SE. Lava flows from a cone within the breached crater reached the north shore of the island. Historical eruptions have been recorded at Chirinkotan since the 18th century. Fresh lava flows also descended the SE flank of Chirinkotan during an eruption in the 1880s that was observed by the English fur trader Captain Snow.

CHIRPOI, Kuril Islands (Russia) 
46.525°N, 150.875°E; summit elev. 742 m

SVERT reported that a thermal anomaly over Snow, a volcano of Chirpoi, was detected in satellite images on 25 and 27 February. Cloud cover obscured views on the other days during 24 February-3 March. The Aviation Color Code remained at Yellow.

Geologic summary: Chirpoi, a small island lying between the larger islands of Simushir and Urup, contains a half dozen volcanic edifices constructed within an 8-9 km wide, partially submerged caldera. The southern rim of the caldera is exposed on nearby Brat Chirpoev Island. Two volcanoes on Chirpoi Island have been historically active. The symmetrical Cherny volcano, which forms the 691 m high point of the island, erupted twice during the 18th and 19th centuries. The youngest volcano, Snow, originated between 1770 and 1810. It is composed almost entirely of lava flows, many of which have reached the sea on the southern coast. No historical eruptions are known from 742-m-high Brat Chirpoev, but its youthful morphology suggests recent strombolian activity.

COLIMA, México 
19.514°N, 103.62°W; summit elev. 3850 m

Based on observations of satellite images and information from the Mexico MWO, the Washington VAAC reported that on 28 February an ash plume from Colima drifted 15 km SE at altitudes up to 4.6 km (15,000 ft) a.s.l. On 1 March two emissions formed an ash plume that drifted over 35 km NNW. Three other plumes drifted NNW later that day.

Geologic summary: The Colima volcanic complex is the most prominent volcanic center of the western Mexican Volcanic Belt. It consists of two southward-younging volcanoes, Nevado de Colima (the 4,320 m high point of the complex) on the N and the historically active Volcán de Colima on the S. Volcán de Colima (also known as Volcán Fuego) is a youthful stratovolcano constructed within a 5-km-wide caldera, breached to the S, that has been the source of large debris avalanches. Major slope failures have occurred repeatedly from both the Nevado and Colima cones, and have produced a thick apron of debris-avalanche deposits on three sides of the complex. Frequent historical eruptions date back to the 16th century. Occasional major explosive eruptions (most recently in 1913) have destroyed the summit and left a deep, steep-sided crater that was slowly refilled and then overtopped by lava dome growth.

DUKONO, Halmahera 
1.68°N, 127.88°E; summit elev. 1335 m

Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 1-2 March ash plumes from Dukono rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted 55-100 km E and SE.

Geologic summary: Reports from this remote volcano in northernmost Halmahera are rare, but Dukono has been one of Indonesia's most active volcanoes. More-or-less continuous explosive eruptions, sometimes accompanied by lava flows, occurred from 1933 until at least the mid-1990s, when routine observations were curtailed. During a major eruption in 1550, a lava flow filled in the strait between Halmahera and the N-flank cone of Gunung Mamuya. Dukono is a complex volcano presenting a broad, low profile with multiple summit peaks and overlapping craters. Malupang Wariang, 1 km SW of Dukono's summit crater complex, contains a 700 x 570 m crater that has also been active during historical time.

ETNA, Sicily (Italy) 
37.734°N, 15.004°E; summit elev. 3330 m

INGV reported that during 28 February-4 March Strombolian activity and diffuse ash emissions continued at Etna's New Southeast Crater (NSEC). An unstable part of the lower E flank of the cone that collapsed on 11 February continued to produce small collapses with reddish ash clouds. Lava continued to flow from a vent on the lower part of the NSEC cone to the W wall of the Valle del Bove, and during 2-3 March the flows reached the base of the wall.

Geologic summary: Mount Etna, towering above Catania, Sicily's second largest city, has one of the world's longest documented records of historical volcanism, dating back to 1500 BC. Historical lava flows cover much of the surface of this massive basaltic stratovolcano, the highest and most voluminous in Italy. Two styles of eruptive activity typically occur at Etna. Persistent explosive eruptions, sometimes with minor lava emissions, take place from one or more of the three prominent summit craters, the Central Crater, NE Crater, and SE Crater. Flank eruptions, typically with higher effusion rates, occur less frequently and originate from fissures that open progressively downward from near the summit. A period of more intense intermittent explosive eruptions from Etna's summit craters began in 1995. The active volcano is monitored by the Instituto Nazionale di Geofisica e Volcanologia (INGV) in Catania.

KARYMSKY, Eastern Kamchatka (Russia) 
54.05°N, 159.45°E; summit elev. 1536 m

KVERT reported that Vulcanian and Strombolian activity at Karymsky continued during 21-28 February. Satellite images detected a daily thermal anomaly on the volcano, and an ash plume that rose to an altitude of 1.5-2 km (3,300-6,600 ft) a.s.l. and drifted 55 km NE. The Aviation Color Code remained at Orange.

Geologic summary: Karymsky, the most active volcano of Kamchatka's eastern volcanic zone, is a symmetrical stratovolcano constructed within a 5-km-wide caldera that formed about 7,600-7,700 radiocarbon years ago. Construction of the Karymsky stratovolcano began about 2,000 years later. The latest eruptive period began about 500 years ago, following a 2,300-year quiescence. Much of the cone is mantled by lava flows less than 200 years old. Historical eruptions have been Vulcanian or Vulcanian-Strombolian with moderate explosive activity and occasional lava flows from the summit crater. Most seismicity preceding Karymsky eruptions has originated beneath Akademia Nauk caldera, which is located immediately S of Karymsky volcano and erupted simultaneously with Karymsky in 1996.

KILAUEA, Hawaii (USA) 
19.421°N, 155.287°W; summit elev. 1222 m

During 26 February-4 March HVO reported that the circulating lava lake occasionally rose and fell in the deep pit within Kilauea's Halema'uma'u Crater. Gas emissions remained elevated. The plume from the vent continued to deposit variable amounts of ash, spatter, and Pele's hair onto nearby areas. At Pu'u 'O'o Crater, glow emanated from spatter cones on the N and S portions of the crater floor; the lava pond in the NE spatter cone was possibly crusted over. The 7.8-km-long Kahauale’a 2 lava flow, fed by the NE spatter cone, stalled in mid-January but remained active with scattered break-out flows behind the flow front that burned adjoining forest.

Geologic summary: Kilauea, one of five coalescing volcanoes that comprise the island of Hawaii, is one of the world's most active volcanoes. Eruptions at Kilauea originate primarily from the summit caldera or along one of the lengthy E and SW rift zones that extend from the caldera to the sea. About 90% of the surface of Kilauea is formed of lava flows less than about 1,100 years old; 70% of the volcano's surface is younger than 600 years. A long-term eruption from the East rift zone that began in 1983 has produced lava flows covering more than 100 sq km, destroying nearly 200 houses and adding new coastline to the island.

SHIVELUCH, Central Kamchatka (Russia)
56.653°N, 161.360°E; summit elev. 3283 m

KVERT reported that during 21-28 February lava-dome extrusion at Shiveluch was accompanied by ash explosions, incandescence, hot avalanches, and fumarolic activity. A bright thermal anomaly was detected daily in satellite images, and a gas-and-steam plume containing small amounts of ash drifted 135 km SE on 25 February. The Aviation Color Code remained at Orange.

Geologic summary: The high, isolated massif of Shiveluch volcano (also spelled Sheveluch) rises above the lowlands NNE of the Kliuchevskaya volcano group and forms one of Kamchatka's largest and most active volcanoes. The currently active Molodoy Shiveluch lava-dome complex was constructed during the Holocene within a large breached caldera formed by collapse of the massive late-Pleistocene Strary Shiveluch volcano. At least 60 large eruptions of Shiveluch have occurred during the Holocene, making it the most vigorous andesitic volcano of the Kuril-Kamchatka arc. Frequent collapses of lava-dome complexes, most recently in 1964, have produced large debris avalanches whose deposits cover much of the floor of the breached caldera. Intermittent explosive eruptions began in the 1990s from a new lava dome that began growing in 1980. The largest historical eruptions from Shiveluch occurred in 1854 and 1964.

SINABUNG, Sumatra (Indonesia) 
3.17°N, 98.392°E; summit elev. 2460 m

Based on wind data, webcam images, and satellite images, the Darwin VAAC reported that during 25 February-1 March and 3-4 March ash plumes from Sinabung rose to altitudes of 3-4 km (10,000-13,000 ft) a.s.l. and drifted 25-55 km E, NE, N, NW, W, and SW.

Geologic summary: Gunung Sinabung is a Pleistocene-to-Holocene stratovolcano with many lava flows on its flanks.  The migration of summit vents along a N-S line gives the summit crater complex an elongated form.  The youngest crater of this conical, 2460-m-high andesitic-to-dacitic volcano is at the southern end of the four overlapping summit craters.  An unconfirmed eruption was noted in 1881, and solfataric activity was seen at the summit and upper flanks of Sinabung in 1912, although no confirmed historical eruptions were recorded prior to 2010.

Source: GVP